The invention pertains to a fixing element for fixing a component on a support part, wherein the fixing element comprises a retaining part for the component to be fixed, a hollow anchor foot for anchoring the fixing element in a continuous bore of the support part, and a spring stop that is arranged between the retaining part and the anchor foot, wherein the wall of the anchor foot contains two opposite openings, wherein two spring arms that are spread apart in the direction of the retaining part respectively originate at the lower edges of the openings, wherein the ends of the spring arms have faces that adjoin the underside of the fixing element after it is inserted into the bore of a support part, and wherein the faces of two diagonally opposing spring arm pairs lie in two different horizontal planes.
Fixing elements of this type are generally known, but are primarily suitable for being fixed in a bore of the support part that has a certain diameter and for a certain material thickness of the support part. This means that specially adapted fixing elements must be respectively manufactured for bores with different diameters and for support parts with different material thicknesses.
DE 201 01 328 U1 discloses a fixing element in which tolerance compensation between the fixing points can be achieved when mounting one planar body on another with the aid of several such fixing elements. This is achieved by realizing the fixing element in two parts and by allowing a certain mobility of the anchor foot in the retaining part perpendicular to the center axis. The anchor foot is prevented from turning in the retaining part by lateral projections on the shaft. Although not required, the outside surfaces of the spring arms may be divided into two sections by a shoulder such that one planar body can assume an intermediate or pre-assembly position relative to other planar body during the installation, wherein the connection is still loose and one body can still be laterally moved in the aforementioned intermediate or pre-assembly position. This is realized by making the diameter defined by the outside surfaces of the spring arms smaller behind the aforementioned shoulder than the diameter of the bore in the body, into which the anchor foot is inserted. The actual fixing of the component takes place in a second step, when a shoulder on the free end of the spring arms engages behind the edge of the bore.
DE 2 153 062 A1 discloses a fixing element in which the free ends of the spread-apart spring arms are concavely bent at the location at which they should come in contact with the edge of the bore in the support part. This allegedly serves to anchor the same fixing element in bores with diameters that vary over a certain range. However, a secure and rigid anchoring cannot be achieved with the curved contact surface of the spring arms; another reason for this is that this publication does not aim to realize anchoring in bores with different diameters of a certain size, but rather with diameters that vary over a certain range. Pairs of laterally and perpendicularly extending projections on the shaft are only able to prevent a horizontal displacement of the anchor foot in a bore with a certain diameter, i.e., in a bore of only one size. The fixing element could not even be installed in a bore with a smaller diameter, and the installation in a bore of larger diameter could lead to the spring arms disengaging due to the lateral play of the anchor foot.
U.S. Pat. No. 2,424,757 discloses a fixing element for fixing a cylindrical component on a plate-shaped support part. The fixing element consists of a sleeve that is pushed onto the cylindrical component and from which a pair of spread-apart spring arms protrudes laterally. The free ends of these spring arms contain several steps. This is intended to allow the anchoring in support parts with different thicknesses. The risk that the spring arms will disengage is also not eliminated in this case such that the component practically cannot be securely fixed in the bore of a support part.
DE 43 07 434 A1 and corresponding publication EP 0 615 071 B1 respectively disclose a holding element that contains an anchor foot in the form of a base body of rectangular cross section. All four lateral surfaces of this base body are provided with snap-in tabs that respectively lie diagonally opposite one another and can be snapped into recesses in the lateral surfaces of the base body. Two opposing snap-in tabs are realized in T-shaped form and have faces that point to the retaining part on the T-crosspieces. This allegedly results in a centering cage effect and consequently a secure retention in the bore of a support part, even if the retaining part turns about its longitudinal axis in the bore. The faces of the snap-in tabs provided may all lie in the same horizontal plane. Alternatively, pairs of snap-in tabs may also lie in different horizontal planes such that the retaining part can be utilized on support parts of different thicknesses.
DE-GM 81 13 637 discloses a holding element that, in theory, also allows the utilization on support parts with different material thicknesses. According to one of the embodiments described in this publication, two pairs of elastic tabs that are directed toward the retaining part are provided on a base body that forms the anchor foot of round cross section, wherein the faces of the elastic tab pairs may also lie in different horizontal planes pair-by-pair. In this case, the first elastic tabs of both elastic tab pairs lie directly adjacent to one another on the circumference of the base body analogous to the other elastic tabs of the elastic tab pairs, i.e., in such a way that the elastic tabs of the shorter elastic pair lie directly opposite of the elastic tabs of the longer elastic pair, i.e., the respective elastic tabs are diagonally offset relative to one another. This is intended to allow a secure retention here in support parts with, specifically, two different material thicknesses. In order to utilize the holding element on support parts with more than two material thicknesses, additional elastic tab pairs with faces may be provided on the circumference of the base body in correspondingly different horizontal planes.
Known holding or fixing elements are designed for use in bores with different diameters in support parts or on support parts of different thicknesses or material thicknesses, the design of these holding or fixing elements is often relatively complicated and their manufacture is correspondingly costly. Nonetheless, a secure and rigid connection still cannot be ensured in all cases.